Catalyzed vapor phase process for making alcohols

ABSTRACT

A catalyzed, continuous vapor phase process to convert a C 2  or higher alcohol and, optionally, one or more C 1  or higher alcohols, for example methanol and ethanol, to a mixture containing at least one higher molecular weight alcohol, for example, isobutanol, over a catalyst which is essentially magnesium oxide. The process also may have a lower aldehyde and/or ketone in the feed.

This is a continuation of application Ser. No. 977,521, filed Nov. 17,1992, now abandoned which is a continuation of application Ser. No.779,980, filed Oct. 21, 1991, now abandoned, which is a divisional ofapplication Ser. No. 702,837filed May 20, 1991, now U.S. Pat. No.5,095,156, which in turn is a continuation of Ser. No. 413,314, filedSep. 27, 1989, and now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to a vapor phase process for catalyticallyconverting one or more lower molecular weight alcohols, optionally incombination with a lower molecular weight aldehyde and/or ether, to amixture containing at least one higher molecular weight alcohol over analkaline catalyst and, more particularly, to a vapor phase, continuousprocess for converting a C₂ or higher alcohol, which may be incombination with one or more additional C₁ or higher alcohols, andoptionally, an aldehyde and/or ether to a mixture containing at leastone higher molecular weight alcohol over a catalyst which is essentiallymagnesium oxide.

In recent years there has been an upsurge in interest in the productionof both chemicals and transportation fuels from non-petroleum carbonsources such as methane, tar sands, oil shale and the like. Thisinterest has focused for lack of good direct conversion processes onindirect processes, which often go through a synthesis gas intermediatewith subsequent conversion of the synthesis gas (Co and H₂) viaFisher-Tropsch and related processes to hydrocarbons and/or oxygenates.Oxygenates, particularly lower alcohols, are common products of suchsynthesis gas reactions, and high conversion, selective processes toconvert an alcohol or a mixture of alcohols to higher molecular weightalcohols have substantial commercial potential.

One potential process uses the well-known, non-catalytic Guerbetreaction which converts a lower molecular weight alcohol to a branchedor linear higher molecular weight alcohol in the presence of an alkalimetal alkoxide dissolved in the alcohol to be converted. Such processesare uncatalysed, moderate temperature batch reactions. When consideredfor industrial use, however, the Guerbet reaction suffers an economicdisadvantage in that a portion of the starting alcohol (and possiblysome of the product) is consumed by oxidation to the correspondingcarboxylic acid unless special agents are added. One publicationsuggests the use of a mixture of potassium hydroxide and boric oxide tosuppress acid formation which is said to improve the yield.

More recently, an improved Guerbet reaction has been reported which usesa "catalyst" system employing magnesium oxide, potassium carbonate, andcopper chromite for converting, for example, ethanol to higher alcoholsincluding 1-butanol, and 1-butanol to higher alcohols including2-ethyl-1-hexanol (J. Org. Chem. 22, 540-2 (1957)). The reaction is ofthe batch type and the "catalyst" is said to have limited lifetime.

Another improvement in the Guerbet reaction, discussed in J. Mol.Catalysis 33, 15-21 (1985), uses a sodium alkoxide mixed with 5% rhodiumon alumina as a "catalyst." A mixture of 1-butanol and methanol is saidto be converted by the "catalyst" to a mixture of 2-ethyl-1-hexanol and2-methyl-1-butanol.

Still other batch Guerbet reaction variations include water removal toimprove yield and the use of an alkali metal hydroxide "catalyst" (U.S.Pat. No. 3,328,470), the use of an alkali metal alcoholate/boric acidester "catalyst" (U.S. Pat. No. 2,861,110), and the addition of a nickel"catalyst" to the metal alkoxide (J. Am. Chem. Soc. 76, 52 (1953).

Octane demand has soared in recent years and the growth is likely tocontinue in the United States. For example, it has been estimated thatclear pool octane demand has been increasing by 0.15 units/year inrecent years. The addition of alcohols and ethers such as methanol,ethanol and methyl t-butyl ether to gasoline to improve octane numberand/or improve the effect of gasoline combustion in internal combustionengines on the environment has been the subject of a number of recentpublications.

Methanol is generally made from synthesis gas and ethanol can be made bycabonylation of methanol or more usually from agricultural products byfermentation. Higher alcohols can also result from the catalyzedconversion of synthesis gas. Methanol, while effective if usedessentially pure for transportation fuel, is not a good additive forgasoline. Ethanol has shown promise as a gasoline additive, butisobutanol in particular is valuable as it can be dehydrated toisobutylene and reacted with methanol to form methyl t-butyl ether(MTBE) which is an excellent octane improver that can be easily blendedinto gasoline. Isobutanol is also an effective octane improver. Themethyl ether of isopentanol (TAME) is also an excellent octane improverfor gasoline. U.K. Patent Application GB 2,123,411 describes a processfor making a mixture of octane improving ethers by synthesizing analcohol mixture containing methanol, ethanol, and higher alcohols anddehydrating the higher alcohols and etherification.

Because of the large amount of methanol available and its problems as agasoline additive, processes which convert methanol to effectivegasoline additives are valuable. Well-known is the Mobil process forconverting methanol to gasoline-range hydrocarbons over analuminum-containing molecular sieve. Little work has been reported oneffectively converting methanol to higher alcohols, in particular,isobutanol.

Now a material has been found which allows a continuous, vapor phase,catalytic Guerbet-type of condensation to be effected on a large varietyof different alcohols, aldehydes and ethers and their mixtures. Inparticular, a catalyst effective in continuously converting a mixture ofalcohols such as methanol and ethanol or a mixture of methanol,formaldehyde, and ethanol in a continuous vapor phase process to higheralcohols has been found which can produce a substantial percentage ofisobutanol in the product. Such a catalyst allows the production of MTBEusing exclusively synthesis gas as the source of carbon to the process.

SUMMARY OF THE INVENTION

The invention described herein is a continuous vapor phase process toconvert a feed comprising a C₂ or higher alcohol, optionally incombination with one or more additional C₁ or higher alcohols to atleast one higher molecular weight alcohol which comprises contactingsaid C₂ or higher alcohol, optionally in combination with one or more C₁or higher alcohols in the vapor phase with a catalyst which isessentially magnesium oxide under condensation conditions to form amixture containing said at least one or more higher molecular weightalcohol.

In another aspect, the invention described herein is a process formaking methyl t-butyl ether from synthesis gas which comprises:

converting said synthesis gas to methanol;

converting part of said methanol to ethanol;

converting said ethanol and part of said methanol in a vapor phase,continuous process to a mixture rich in isobutanol over a condensationcatalyst;

dehydrating said isobutanol to isobutene after separation from saidmixture; and

reacting said isobutene and said methanol to form said methyl t-butylether.

DESCRIPTION OF THE DRAWING

The FIGURE shows a simplified flow diagram for one embodiment of theinvention in which synthesis gas is converted to MTBE using thecontinuous magnesium oxide-based, catalyzed, vapor phase condensationprocess.

DETAILED DESCRIPTION OF THE INVENTION

The C₂ or higher alcohols useful herein are C₂ to C₂₀ alcohols such asethanol, a propanol, a butanol, a pentanol, a hexanol, a nonanol, adodecanol, and the like. The only limitation on such alcohols is theirability to be vaporized and passed over the catalyst at a temperaturelow enough to avoid substantial decomposition. The C₁ or larger alcoholsused in the invention include all of the above and methanol. The C₁ toC₄ aldehydes and C₁ to C₆ ethers generally include aldehydes and etherssuch as formaldehyde, acetaldehyde, propionaldehyde, dimethyl ether,diethyl ether, methyl ethyl ether, methyl isopropyl ether, and the like.More preferred for the C₂ or higher and C₁ or higher alcohols are C₁ toC₈ alcohols including methanol, ethanol, propanol, n-butanol,2-methylpropanol, n-pentanol, 3-methylbutanol, n-pentanol and the like.An especially preferred feed is a mixture of methanol, ethanol, andformaldehyde, a mixture of methanol and ethanol, a mixture of methanol,ethanol, and a propanol, or an effluent from a synthesis-gas-to-alcoholsconversion process which contains methanol, ethanol and amounts of C₂ +alcohols. The feed to the process may in addition contain small amountsof one or more of methane, oxygen, nitrogen, hydrogen, carbon monoxideand carbon dioxide.

In general, after the feed is passed over the catalyst it will contain amixture of alcohols at least one of which is of higher molecular weightthan any of the starting alcohol or alcohols. For example, a mixture ofmethanol and ethanol and a mixture of methanol, formaldehyde and ethanolproduces at least 1-propanol, and a mixture of methanol, ethanol, and1-propanol produces at least isobutanol; a mixture of methanol andisopropanol produces at least 2-butanol; ethanol alone produces at leastn-butanol; n-butanol alone produces at least 2-ethylhexanol, andpropanol alone produces at least 2-methylpentanol. Small amounts ofnon-alcohol products such as aldehydes, ethers and ketones generallyalso occur in the product.

The magnesium oxide component useful in the catalyst herein described isessentially magnesium oxide. The magnesium oxide is present as more thanabout 80, more preferably more than about 90, and most preferably, morethan about 95 wt. % of the total catalyst weight. The catalyst may alsocontain minor amounts of magnesium hydroxide, or alkaline materials suchas a Period Group Ia or Group IIa compound including oxides andhydroxides. The magnesium oxide component is preferably of highersurface area, more preferably of surface area greater than about 25 sqm/g, and most preferably, of surface area above about 50 sq m/g, asmeasured by the BET method with nitrogen.

The magnesium oxide can be made by calcination of magnesium hydroxide oranother magnesium compound such as magnesium carbonate or acetate. Thepreferred magnesium compound is magnesium hydroxide. The calcinationtemperature of the magnesium compound used should not be greatly inexcess of the temperature needed to produce the oxide as the oxide canbe produced in a less active form.

The catalyst may be used neat, but can be admixed with a diluent such aszirconia, titania, boria, alumina, and, particularly, a carbonaceousmaterial such as charcoal and the like. Such diluents need not becompletely inert and, indeed, it appears that the use of charcoal as adiluent improves certain of the condensation reactions described hereinsuch as that of a mixture of methanol and ethanol, and a mixture ofmethanol, ethanol and a propanol. The diluent and the magnesium oxidecomponent may be admixed in proportions of from 100 wt. % magnesiumoxide component and no diluent to about 10 wt. % magnesium oxidecomponent and about 90 wt. % diluent. More preferably, the proportionsmay vary between about 80 wt. % magnesium oxide component and about 20wt. % diluent to about 20 wt. % magnesium oxide component and about 80wt. % diluent.

The magnesium oxide component may in addition be supported on suchsupports as titania, alumina, silica, boria, zirconia, and acarbonaceous material such as charcoal and the like, by impregnation orotherwise. Magnesium oxide component/support wt. % ratios are generallythe same as described above for catalysts wherein the magnesium oxidecomponent is admixed with a diluent.

Use of a carrier gas mixed with the feed to the process can beadvantageous. Such materials as hydrogen, carbon monoxide, carbondioxide, a hydrocarbon, and inert gases such nitrogen, argon, and thelike may be used to improve the condensation reaction. The use ofhydrogen in the process can improve selectivity and, if used, isgenerally employed in a hydrogen/feed ratio of from about 20:1 to about1:1, more preferably, about from 10:1 to about 1:1.

The catalyst, with or without a carrier gas added to the feed, can beused in a fixed bed, ebullated bed, fluidized bed, or other type ofvapor phase process. A copper-walled reactor has been found to bebeneficial. In general, the temperature range useful in carrying out thecondensation reaction described herein runs between about 300° and about700° C., more preferably, between about 300° and about 500° C., and mostpreferably, between about 325° and about 450° C. The range of totalreactor pressure useful in this invention runs between subatmosphericand about 1000 psig, more preferably, between subatmospheric and about600 psig, and most preferably, subatmospheric to about 500 psig. Usefulweight hour space velocities run between about 0.05 and about 50 hr⁻¹,and more preferably, between about 0.05 and about 10 hr⁻¹, based uponthe magnesium oxide component in the catalyst.

A particularly useful process which may be carried out employing thecondensation reaction is the production of MTBE from synthesis gas asthe sole carbon source. In such a process, synthesis gas is converted tomethanol which is converted, for example, by carbonylation to ethanol.The ethanol is then condensed using a condensation catalyst such as theone disclosed herein with methanol to form a mixture rich in isobutanol.Other catalysts may also be used. The isobutanol may then be separatedfrom the mixture, dehydrated, and reacted with additional methanol toform MTBE. One possible process of accomplishing production of MTBE isset out below to illustrate this use. The description of such process isnot meant to limit the invention in any way.

In the FIGURE, synthesis gas (H₂ and CO) is added to gas separationsection 2 where the synthesis gas is separated into a CO rich and a COdepleted fraction exiting through lines 3 and lines 4 respectively. Theseparation can be effected in any one of several ways including, but notlimited to, pressure swing absorption, membrane removal of hydrogen,cryogenic separation, or a chemical separation such as that employingthe COSORB technology, as may be understood by one skilled in the art.The CO depleted stream (line 4) goes to methanol synthesis section 5where any of the commercial technologies to convert synthesis gas(especially hydrogen-rich synthesis gas) to methanol can be used.Methanol synthesis produces methanol exiting through line 6 and ahydrogen-rich purge stream 7. A portion of the methanol exiting throughlines 6 goes into line 6' and is reacted with the CO rich stream of line3 in carbonylation section 8 using any of the available carbonylationtechnologies to produce acetic acid or methyl acetate as may beunderstood by one skilled in the art. The latter acid or ester exitsthrough line 9 to hydrogenolysis section 10 and is reacted with hydrogenentering hydrogenolysis section 10 through line 7 to form ethanol or amixture of methanol and ethanol which exits through line 11. It ispreferred to combine carbonylation and hydrogenolysis in a single step.The methanol and ethanol in line 11 are mixed with additional methanolfrom methanol synthesis section 5 through lines 6, 12 and 13 incatalytic condensation section 14 which contains a magnesium oxide-basedcatalyst. Catalytic condensation section 14 is generally run at a highmethanol to ethanol ratio to suppress formation of n-butanol. Theeffluent from catalytic alcohol condensation section 14 is transferredthrough line 15 to separation section 16 where it can be fractionated.The isobutanol and isopentanol portion of the fractionation in section16 is sent via line 17 to dehydration section 18 where the alcohols aredehydrated using a conventional alcohol dehydration technology, and theolefins produced are transferred through line 19 to MTBE formationsection 20. MTBE formation section 20 uses methanol for addition to theolefins which comes to section 20 through line 12. MTBE and the methylether of isopentanol (TAME) are removed through line 21. Other alcoholsthan isobutanol and isopentanol which are produced in catalytic alcoholcondensation section 14 are separated during the fractionation inseparation section 16 and recycled to the feed of section 14 throughline 22.

The following Examples will serve to illustrate certain specificembodiments of the herein disclosed invention. These Examples shouldnot, however, be construed as limiting the scope of the novel inventioncontained herein as there are many variations which may be made thereonwithout departing from the spirit of the disclosed invention, as thoseof skill in the art will recognize.

EXAMPLES General

All catalysts were evaluated in a fixed bed, continuous, down flow,stainless steel reactor. For some of the studies the stainless steelreactor was equipped with either a quartz or a copper liner. Thecatalyst was ground to 12/20 mesh size and physically mixed with beddiluent, charcoal, or alumina of the same mesh size. The catalyst bedwas centered in the reactor with an inert alumina balls baffle above andbelow it for improved heat transfer. The alumina balls were kept at alower temperature than the catalyst bed. The unit was pressured withhelium unless otherwise noted and the catalyst brought to reactiontemperature in flowing helium, at which time the alcohol was introducedvia a Ruska pump.

Products were analyzed by three gas chromatographic systems. The fixedgases, CO and CO₂ along with CH₄ were analyzed by an on-lineHewlett-Packard 5730 gas chromatograph equipped with a thermalconductivity detector and a Chromosorb 106 packed column. Analysis wasaccomplished by using an external standard calibrated for CO, CO₂ andCH₄. The noncondensible light gases, C₁ -C₆, were analyzed off-lineusing a flame ionization detector and a 6 ft N-octane Porosil C column.The peaks were identified and measured by matching retention times withan external standard containing C₁ -C₆ hydrocarbons.

The condensible materials were collected in a bomb and analyzed with aflame ionization detector equipped with a 30 m capillary column of fusedsilica containing RSL 160 liquid phases. Peaks were identified bymatching retention times of known alcohols, aldehydes, esters, ketones,olefins and paraffins. Many smaller peaks were not identified. Theresults are expressed in relative weight percents.

The condensible liquids were also measured on a Hewlett-Packard 5730 gaschromatograph equipped with a thermal conductivity detector. A 6 ft×1/8in Poropak QS column, 80/100 mesh particles, was used. This system gavesemiquantitative results for water, C₁ -C₅ alcohols, and some of thelower molecular weight aldehydes, ketones and esters.

Example 1

Magnesium oxide was prepared from 25 kg of commercially availablemagnesium hydroxide (VWR Scientific, Inc. reagent grade powder) by firstmixing with 2000 g of distilled water and extruding the mass through a1/8 in die plate. The extrudate was dried overnight at 120° C. andcalcined first at 300° C. for 1 hr and then 450° C. for 12 hr. Theresulting MgO having a BET surface area of 29 m² /g was used forExamples 2-6.

Example 2

A 3.23 g (5 ml) quantity of magnesium oxide was mixed with 29 ml ofcharcoal supplied by Sargent-Welch as the catalyst. A 3/1 methanol toethanol reactor feed and a copper lined reactor were used for thisExample.

                  TABLE 1                                                         ______________________________________                                        Temperature °F.    800                                                 Pressure                  150 psig                                            Helium Flow               0.099 ft.sup.3 /hr                                  WHSV (hr.sup.-1)          2.5                                                 Wt % Methanol Converted   22.4                                                Wt % Ethanol Converted    99.5                                                Wt % Selectivity (Water-Free Basis) of Products                               1-Propanol                8.3                                                 Isobutanol                31.6                                                1-Butanol                 0                                                   t-Butanol                 5.4                                                 CO + CO.sub.2             22.1                                                Methane                   5.4                                                 Ethane + Ethylene         3.1                                                 Propane                   6.5                                                 Propylene                 1.2                                                 C.sub.4 Hydrocarbons      4.3                                                 C.sub.5 + Hydrocarbons    2.1                                                 Acetaldehyde              0                                                   Other                     10.0                                                ______________________________________                                    

Example 3

Alcohol conversion is a function of space velocity and diluent characterfor the reaction of ethanol and methanol was studied and the results areshown in Tables 2, 3, and 4 below. A 3/1 methanol to ethanol reactorfeed composition was used.

                  TABLE 2                                                         ______________________________________                                        Conversion as a Function of Space Velocity                                    and Bed Diluent in a Copper Reactor                                           WHSV   % Methanol Converted                                                                           % Ethanol Converted                                   (hr.sup.-1)                                                                          Neat   Charcoal Alumina                                                                              Neat Charcoal                                                                             Alumina                             ______________________________________                                        0.6    9      41       --     35   100    --                                  2.5    3      22       --     21   99     --                                  4.1    --      3       --     --   43     --                                  ______________________________________                                    

                  TABLE 3                                                         ______________________________________                                        Conversion as a Function of Space Velocity                                    and Bed Diluent in a Stainless Steel Reactor                                  WHSV   % Methanol Converted                                                                           % Ethanol Converted                                   (hr.sup.-1)                                                                          Neat   Charcoal Alumina                                                                              Neat Charcoal                                                                             Alumina                             ______________________________________                                        0.6    32     99       --     54    99    --                                  2.5     9     82       32     25   100    59                                  ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        Conversion as a Function of Space Velocity                                    and Bed Diluent in a Quartz Reactor                                           WHSV   % Methanol Converted                                                                           % Ethanol Converted                                   (hr.sup.-1)                                                                          Neat   Charcoal Alumina                                                                              Neat Charcoal                                                                             Alumina                             ______________________________________                                        0.6    23     5        --     63   13     --                                  2.5    12     1        --     37    4     --                                  ______________________________________                                    

Example 4

The effect of a bed diluent on product distribution in a copper-linedreactor for the reaction of ethanol and methanol is given in Table 5below. A 3/1-methanol to ethanol reactor feed was used.

                  TABLE 5                                                         ______________________________________                                        Effect of Bed Diluent on Product                                              Selectivity in a Copper Reactor                                                                              Char-                                          Bed Diluent            None    coal                                           ______________________________________                                        Temperature °F. 800     800                                            WHSV (hr.sup.-1)       2.5     2.5                                            Wt % Methanol Converted                                                                              3.3     22.4                                           Wt % Ethanol Converted 21.4    99.5                                           Wt % Selectivity (Water-Free Basis) of                                        Products                                                                      1-Propanol             35.4    8.3                                            Isobutanol             2.5     31.6                                           1-Butanol                                                                     t-Butanol                      5.4                                            CO + CO.sub.2          14.2    22.1                                           Methane                1.5     5.4                                            Ethane + Ethylene      3.1     3.1                                            Propane                0       6.5                                            Propylene              0.7     1.2                                            C.sub.4 Hydrocarbons   0       4.3                                            C.sub.5 + Hydrocarbons 0       2.1                                            Acetaldehyde           17.8    0                                              Other                  17.5    10.0                                           ______________________________________                                    

Example 5

The effect of a bed diluent on product distribution on the reaction ofethanol and methanol in a quartz reactor is given below in Table 6. A3/1 methanol to ethanol reactor feed was used.

                  TABLE 6                                                         ______________________________________                                        Effect of Bed Diluent on Product                                              Selectivity in a Quartz Reactor                                                                              Char-                                          Bed Diluent            None    coal                                           ______________________________________                                        Temperature °F. 800     800                                            WHSV (hr.sup.-1)       0.6     0.6                                            Wt % Methanol Converted                                                                              23.5    5.3                                            Wt % Ethanol Converted 62.5    13.4                                           Wt % Selectivity (Water-Free Basis) of                                        Products                                                                      1-Propanol             0       0                                              Isobutanol             0       0                                              1-Butanol              0       0                                              t-Butanol              0       0                                              CO + CO.sub.2          41.8    29.6                                           Methane                4.0     5.9                                            Ethane + Ethylene      2.2     3.1                                            Propane                0.2     9.3                                            Propylene              0.6     0                                              C.sub.4 Hydrocarbons   0.1     2.3                                            C.sub.5 + Hydrocarbons 0.1     0                                              Acetaldehyde           49.5    49.8                                           Other                  1.5     0                                              ______________________________________                                    

Example 6

The effect of differing bed diluents on the reaction of methanol andethanol in a stainless steel reactor is given below in Table 7. A 3/1methanol to ethanol reactor feed was used.

                  TABLE 7                                                         ______________________________________                                        Effect of Bed Diluent on Product                                              Selectivity in a Stainless Steel Reactor                                                                  Char-                                             Bed Diluent         None    coal    Alumina                                   ______________________________________                                        Temperature °F.                                                                            800     800     800                                       WHSV (hr.sup.-1)    2.5     2.5     2.5                                       Wt % Methanol Converted                                                                           7.6     90.6    29.0                                      Wt % Ethanol Converted                                                                            20.4    99.1    54.6                                      Wt % Selectivity (Water-Free Basis)                                           of Products                                                                   1-Propanol          21.1    0.1     3.0                                       Isobutanol          0       0.8     0                                         1-Butanol           0       0       0                                         t-Butanol           0       0       0                                         CO + CO.sub.2       35.8    67.7    57.6                                      Methane             10.2    12.6    6.9                                       Ethane + Ethylene   5.6     5.4     2.7                                       Propane             0.1     2.0     0.3                                       Propylene           0.8     3.4     2.5                                       C.sub.4 Hydrocarbons                                                                              0       2.5     0.4                                       C.sub.5 + Hydrocarbons                                                                            0.2     1.8     0.5                                       Acetaldehyde        9.4     0.3     18.2                                      Other               16.6    3.3     7.7                                       ______________________________________                                    

Example 7

A 500 g portion of magnesium hydroxide powder supplied by Sargent-Welshwas placed in a beaker, treated with water no make a thick paste, andthen dried at 130° C. A first portion of it was calcined at 450° C. for12 hr and a second portion was calcined at 538° C. for 12 hr. The lattermaterial shows a pore volume of 0.9793 cc/g, an average pore radius of197 Å, and a BET (nitrogen) surface area of 90 m² /g. Both calcinationproducts were crushed and sieved to 18/40 mesh granules.

Example 8

Both MgO products of Example 7 were loaded into a quartz reactor, and a3/1 methanol to ethanol feed passed over the catalyst for 1 hr at 450°C. The results are set out below in Table 8.

                  TABLE 8                                                         ______________________________________                                        Effect of Calcination Temperature                                             on Product Distribution                                                                       538° C. Product                                                                    450° C. Product                            Component       (%)         (%)                                               ______________________________________                                        acetaldehyde    0.75        *                                                 propionaldehyde 0.59        *                                                 isobutyraldehyde + acetone                                                                    0.47        1.48                                              methanol        50.6        36.11                                             ethanol         17.4        3.66                                              n-propanol      10.3        5.68                                              isobutanol      7.63        29.4                                              allyl alcohol   1.0         *                                                 n-butanol       1.78        0.62                                              2-Me-1-butanol  3.13        6.35                                              ______________________________________                                         *not measured                                                            

Example 9

A 73.58 g portion of Al(NO₃)₃.9 H₂ O was dissolved in 140 g of water. A130.25 g portion of magnesium hydroxide was slowly added to the solutionuntil a solid paste was formed. Additional water and the remaininghydroxide were added until the thick paste was again formed. The pastewas dried at 121° C. and calcined 12 hr at 538° C. The product catalystcontains about 10 wt. % aluminum oxide.

Example 10

A 5/1 methyl alcohol/diethyl ether mixture (0.0126 ml/min of mixture, 6ml/min of nitrogen) was passed over 9.4 ml of catalyst in a quartzreactor at 430° C. and ambient pressure for 140 min giving 0.94 g ofliquid product in a dry ice-isopropanol trap. The product distributionis given below in Table 9.

                  TABLE 9                                                         ______________________________________                                        Liquid Product Component                                                                          Wt. %                                                     ______________________________________                                        methyl ether        5.79                                                      methyl ethyl ether  3.62                                                      diethyl ether       41.7                                                      methyl n-propyl ether                                                                             1.53                                                      methyl isobutyl ether                                                                             2.41                                                      propionaldehyde     0.67                                                      isobutyraldehyde + acetone                                                                        0.84                                                      methanol            31.4                                                      ethanol             4.51                                                      n-propanol          2.21                                                      isobutanol          4.62                                                      2-Me-1-butanol      0.27                                                      ______________________________________                                    

Example 11

A 2/1 methanol/n-butanol mixture (0.0126 ml/min of mixture, 6 ml/min ofnitrogen) was passed over the 538° C. calcined MgO catalyst of Example 7at 425° C. and ambient pressure for 60 min giving 0.77 g of liquidproduct in a dry ice-isopropanol trap. The product distribution is shownin Table 10 below:

                  TABLE 10                                                        ______________________________________                                        Liquid Product Component                                                                          Wt. %                                                     ______________________________________                                        methyl alcohol      24.7                                                      isopropanol         0.88                                                      n-butanol           45.8                                                      2-Me-1-butanol      19.3                                                      2-Me-1-pentanol     1.54                                                      ______________________________________                                    

Example 12

Ethanol (0.0126 ml/min, 6 ml/min of nitrogen) was passed over the 538°C. calcined magnesium oxide of Example 7 at 425° C. and ambient pressurefor 105 min giving 0.82 g of liquid product trapped in a dryice-isopropanol trap. The product distribution is shown below in Table11.

                  TABLE 11                                                        ______________________________________                                        Liquid Product Component                                                                          Wt. %                                                     ______________________________________                                        acetaldehyde        1.4                                                       propionaldehyde     0.6                                                       i-butyraldehyde + acetone                                                                         0.78                                                      n-butyraldehyde     0.6                                                       methanol            1.7                                                       2-butanone          0.87                                                      2-propanol          2.4                                                       ethanol             39.6                                                      methyl vinyl ketone 0.9                                                       2-pentanone         1.2                                                       2-butanol           1.0                                                       n-propanol          1.0                                                       crotonaldehyde      0.67                                                      allyl alcohol       1.59                                                      mesityl oxide       0.48                                                      n-butanol           14.8                                                      2-methyl-1-butanol  0.78                                                      ______________________________________                                    

Example 13

A 5/1/1 methanol, ethanol, and 1-propanol mixture (0.0126 ml/min, 6ml/min of nitrogen) was passed over the 538° C. calcined magnesium oxideof Example 7 at 425° C. and ambient pressure for 120 min giving 1.36 gof liquid product trapped in a dry ice-isopropanol trap. The productdistribution is shown below in Table 12.

                  TABLE 12                                                        ______________________________________                                        Liquid Product Component                                                                          Wt. %                                                     ______________________________________                                        acetaldehyde        0.67                                                      methyl n-propyl ether                                                                             0.98                                                      ethyl n-butyl ether 1.17                                                      isobutyraldehyde + acetone                                                                        1.35                                                      methanol            37.4                                                      ethanol             6.74                                                      i-propanol          13.2                                                      i-butanol           24.1                                                      2-Me-1-butanol      2.04                                                      2-Me-1-pentanol     2.19                                                      ______________________________________                                    

That which is claimed is:
 1. A process for making methyl t-butyl etherfrom synthesis gas comprising a mixture of carbon monoxide and hydrogenwhich process comprises:converting synthesis gas to methanol; convertingpart of the methanol to ethanol by carbonylation of methanol andhydrogenolysis of products of carbonylation; converting the ethanol andpart of the methanol in a vapor phase, continuous process undercatalytic alcohol condensation conditions to a mixture rich inisobutanol over a condensation catalyst comprising magnesium oxidehaving surface area above about 25 square meters per gram and made bycalcination of magnesium hydroxide in the temperature range from aboveits decomposition temperature to 538° C.; dehydrating the isobutanol toisobutene after separation from the mixture; and reacting the isobuteneand part of the methanol to form the methyl t-butyl ether.
 2. Theprocess of claim 1 wherein said condensation catalyst is essentiallymagnesium oxide.
 3. A process to produce a stream containing methylt-butyl ether useful as a gasoline component from synthesis gas whichcomprises a mixture of carbon monoxide and hydrogen (CO and H₂)comprising:separating the synthesis gas into a CO-rich synthesis gasfraction and a CO-depleted synthesis gas fraction (hydrogen-richsynthesis gas); converting the CO-depleted synthesis gas fraction into amethanol stream and a hydrogen-rich purge gas stream; carbonylating aportion of the methanol stream with the CO-rich synthesis gas fractionto produce a hydrogenolysis feed stream containing acetic acid or methylacetate; converting the hydrogenolysis feed stream by hydrogenolysis toan ethanol-containing stream; condensing of the ethanol-containingstream with a portion of the methanol stream to form a C₅alcohol-containing stream under vapor phase reaction conditions in thepresence of magnesium oxide-based catalyst, the catalyst comprisingmagnesium oxide having surface area above about 25 square meters pergram and made by calcination of magnesium hydroxide at temperatures in arange upward from its decomposition temperature to 538° C.;fractionating the C₅ alcohol-containing stream to obtain a dehydrationfeed fraction rich in isobutanol and isopentanol, and a recycle fractionof other alcohols than isobutanol and isopentanol; dehydrating thedehydration feed fraction to form an olefin-containing stream; andreacting the olefin stream with a portion of the methanol stream to forma product stream containing methyl t-butyl ether (MTBE) and the methylether of isopentanol (TAME):wherein hydrogen in the hydrogen-rich purgegas stream is used in the hydrogenolysis, and wherein the recyclefraction is admixed with the ethanol-containing stream.
 4. The processaccording to claim 3 wherein the condensing of the ethanol-containingstream with a portion of the methanol stream is carried out continuouslyusing weight hour space velocities in a range from about 0.05 hr⁻¹ toabout 50 hr⁻¹, based upon the magnesium oxide component in the catalyst.5. The process according to claim 4 wherein the vapor phase conditionsof reaction comprise total pressures in a range from subatmospheric toabout 1000 psig, and temperatures in a range from about 300° C. andabout 500° C.
 6. The process according to claim 5 wherein the magnesiumoxide-based catalyst further comprises from about 10 percent to about 90percent charcoal and from about 90 percent to about 10 percent magnesiumoxide, and wherein the condensing of the ethanol-containing stream witha portion of the methanol stream is in the presence of a copper surface.7. A process to produce an organic composition useful as a gasolinecomponent to improve octane number and/or improve the effect of gasolinecombustion in internal combustion engines on the environment, fromsynthesis gas which comprises a mixture of carbon monoxide and hydrogenthe process comprising:separating the synthesis gas into a carbonmonoxide-rich synthesis gas fraction and a hydrogen-rich synthesis gasfraction (carbon monoxide-depleted synthesis gas); converting thehydrogen-rich synthesis gas fraction into a methanol stream andseparating therefrom a hydrogen-rich purge gas stream; carbonylating aportion of the methanol stream with the carbon monoxide-rich synthesisgas fraction to produce a carbonylation product stream containing aceticacid or methyl acetate; converting the carbonylation product stream byhydrogenolysis to an ethanol-containing stream; condensing theethanol-containing stream with a portion of the methanol stream in thepresence of magnesium oxide-based catalyst, the catalyst comprisingmagnesium oxide having surface area above about 25 square meters pergram and made by calcination of magnesium hydroxide at temperatures in arange from its decomposition temperature to 538° C., under conditions ofcontinuous, vapor phase condensation reaction comprising weight hourspace velocities in a range from about 0.05 to about 10 hr⁻¹, based uponthe magnesium oxide component in the catalyst, total pressures in arange from sub-atmospheric to about 600 psig, and temperatures in arange from about 325° C. and about 450° C. to form a C₅alcohol-containing stream; fractionating the C₅ alcohol-containingstream to obtain a dehydration feed fraction rich in isobutanol andisopentanol, and a recycle fraction of other alcohols than isobutanoland isopentanol; admixing the recycle fraction of other alcohols thanisobutanol and isopentanol with the ethanol-containing stream;dehydrating the dehydration feed fraction to form an olefin-containingstream; and reacting the olefin stream with a portion of the methanolstream to form an organic composition product containing methyl t-butylether (MTBE) and the methyl ether of isopentanol (TAME):wherein thehydrogen-rich purge gas stream is used in the hydrogenolysis of thehydrogenolysis feed stream.
 8. The process according to claim 7 whereinthe magnesium oxide-based catalyst further comprises charcoal as adiluent in proportions between 80 weight percent magnesium oxide andabout 20 weight percent charcoal to about 20 weight percent magnesiumoxide and 80 weight percent charcoal, and the magnesium oxide componenthas a surface area above about 25 square meters per gram as measured bythe BET method with nitrogen.
 9. The process according to claim 8wherein the condensing of the ethanol-containing stream with a portionof the methanol stream is carried out continuously using a carrier gasadmixed with the alcohol feed streams to the continuous condensationreaction, the carrier gas comprises hydrogen, and the carrier gas isemployed at a flow rate which provides a hydrogen to feed ratio in arange from about 10:1 to about 1:1.
 10. The process according to claim 9wherein the condensing of the ethanol-containing stream with a portionof the methanol stream is carried out in presence of a copper surface.